The acquirement of spiritual wisdom does not necessarily prevent us from making worldly mistakes; but because it develops the qualities that will prevent them, and because it takes to heart the lessons of experience, humbly and receptively, it does reduce the frequency of those mistakes.
God is the friend of silence. See how Nature -- trees, flowers, and grass -- grow in stillness; how stars, moon, and sun run their course in silence. The more we receive through quiet prayer, the more we can give in the activity of our daily lives. In essence, it is not what WE say, but what GOD says in us and through us. All our words are useless if they do not come from within.